1. depends on how strong they are and what make etc also proper maintenance will help.
2. for a begginers start by pointing the pedals down with your feet and them push back and up at the same time. also lean forward.
3. start bouncing trying to find your balance on the back wheel, by endoing into it etc, then learn to pedal kick by lowering your front end down while leaning back then kick and jump.
4. not sure